Liquid hydrogen fluoride composition



Patented May 17, 1949 UNITED STATES LIQUID- HYDRO GEN-"FLUORIDE comosrrrow Carl B. Linn, Riverside, Ill.,\ assignor to.Universal OilProductsCompany, Chicago,.1ll.',.a corporation of'Delaware 6 Claims.

This. application is.a1 division of my copend-ing application Serial. No. 596,924;v nowPatent No. 21421351, filed.'May 31, 19.45,. as a continuationin-part of my application SerialNo. 424,784, filed D'ecem'berZQ; 1941,.and1now Patent Number "2 and as by-products of various. chemical industries. Normally, gaseous mono-olefins, 'suchas propylene and" butylenes, and'normally liquid olefins including, amylenes; hexenes, and higher olefins, may be obtained also; by' catalytic, dehydro- 5 2',398",'90'5, grantedlAprili23;1.946.. genation of'parafi'ins, by pyrolysis'of certainpar- This invention relates to'the polymerization of afiinic hydrocarbons, and by dehydration of alolefinic hydrocarbons inthe presence ofa special cohols. Polfyolefins andcyclic'olefins are also-oletype of catalyst. More. particularly, this invenfinic hydrocarbons which may be polymerized in tionrelates' toftlrie polymerization of propylene my process and these include particularlybuand butylenesrintolnormallyliquid hydrocarbons tadiene,. isoprene, cyclohexene, alkyl 'cycl'ohexboiling. within the-approximate. range of gasoenes,. etc. ling. If t i thi t t 1 In geggral, olefins.1 have I: reliatlivtely liliiih acn 0 ice 0 sinven ion..is. o. po ymerize tivity a even. un er mi ;'ca a y ic i uence olefinic hydrocarbons: in the presence. of a liquid they exhibit this activity by their pronounced catalytic: material. tendency to. polymerize and form. substances of Another object oithis invention is to convert higher. molecular'weights. This process is par gropylgneand'tbgitylenesintofnoi'malllylimuid ihyticul'arly efi'eijctive. for. confiertitil'lg plropylene g rtild rocar onsin e presence 0 .a' iqu-i ca a ys butylenes in o normally qui po ymers. 'e A further. object. oithis invention. is topolypresent. process. is directed particularly .to the merize olefinic hydrocarbons including monoproduction of polymers containing from about 6 olefitns. ans. polyolefins. mttlliedpresencg of. a cattoaboutlz .andlmorecar-bon atoms per molecule re m1X ure pri in y rogen. uoride. from. propylene and butylenes. The preferred In one. specific. embodiment thisinvention repolymer. products boil. at temperatures within the latesto. aprocessfor producing hydrocarbons of .25 approximatev boiling rangeof commercial gasohigher molecular weight which comprises reactline, These polymers, containing from about.6 ing olefinic hydrocanbomhavingleast 3 to about 12 carbon atoms per molecule areuse- Gabon @mmspfir molecul? polymenzmg- 9 ful for blending with straight-run gasoline to ditions. m.the presenceof liquid hydrogenfluoride d increase its antiknock value. and a..c1on.';:pgu:rf1d sohllallem said hydrogenifluoride By the addition toJiquid hydrogen fluoride of id Se g 8 i fi if g g the the herein described non-oxidizing acids, anhyz i 05p an y n es and drides, and esters, the ordinarily vigorous activity Another. embodiment of this invention relates of hydroggn fluonde m catalymg'pdymerizimn of olefins is moderated. Thus I have found that to-avpolymerizatwnprocess which comprises-re- .35 i

substantialyields of liquid polymers of relatively acting an. olefimc. hydrocarbon having at least I low molecular weights are produced when'propyl- 3 carbon atomsper. molecule 1n the presence of ene, butylenes, and higher'olefins are reacted at a maJor. proportion by. weight of liquid hydrogen a o r V temperatures of from about -50 to about 250 C. fiuor1de..and..-a minor. proportion. by weightof t 1 t t f f b a substantially non-oxidizing compound selected 40 bu f g empera ure 0 a i from the groupconsisting. of, the. acids. of..phosl 15 h he mesence of '9 alys. comphorus and their anhydrides and esters, j f g i major'pt'oportmnbyweight A further embodiment of this invention relates a .propoflfionfiby to a polymerization. process which comprises re- Welght of an mdwf1Ph9SPhm1tS f d or actinga monogolefinic hydrocarbon havingv at ester; The;polymenzatmntreatment1s.generally least 3 carbonatoms per molecule inthe presence earned P pressure sumci'ent' to' of a liquid hydrogenfluoride. catalyst having disthe reactmg' hydrocarbonsfand catalyst m Solved therein a minor proportion by weight f stantially liquid phase; Also, the treatment of an acid f phosphorus. the olefinic charging stock" in the presence-.otthe Normally gaseous and" liquid hydroc catalyst utilizes a contact time-of from about 40 which are. polymerizable. by the. process of. the seconds asl'ong sfi p d pon present inventiontoccur together with paraflinic the nature of olefinic'ch'arging S k o or saturated hydrocarbons incommercial hyd'roupon the pr perti'esof the desired product; The carbon mixturessuchasthose encountered'tin the acid of phosphorus; its anhydride or ester which cracking of petroleumin gas. making processes, 5 -is-.herein.referred"to as'a" spacing agent or: diluent,

3 is present to the extent of from about 1 to about 50% by weight of the hydrogen fluoride used.

Accordingly, the present invention deals with a hydrogen fluoride polymerizing catalyst of controlled activity which is modified by the addition to said hydrogen fluoride of a compound soluble therein and selected from the group consisting of the acids of phosphorus and their anhydrides and esters. The substantially non-oxidizing inorganic acids utilizable in the present process include acids of phosphorus, such as phosphorous, orthophosphoric, pyrophosphoric, and tetraphosphoric acids, more complex acids of phosphorus, the anhydrides of acids of phosphorus, and esters of the various acids of phosphorus.

The addition of these compounds or spacing agents to liquid hydrogen fluoride influences the polymerization of monoolefinic hydrocarbons in such a way as to improve the yield and quality of relatively low boiling normally liquid hydrocarbons. In fact, the polymers formed in the presence of my catalyst mixture comprising hydrogen fluoride and a spacing agent differ considerably from polymers formed from the same olefinic charging stock but in the presence of substantially anhydrous hydrogen fluoride and in the absence of a spacing agent. In the presence of my mixed catalyst, mono-olefinic hydrocarbons are converted into polymers comprising essentially the mono olefinic hydrocarbons, whereas in the presence of substantially anhydrous hydrogen fiuoride, the same monoolefinic hydrocarbon charging stock undergoes what may be termed conjunct polymerization and forms a complex mixture of hydrocarbons containing paraflins, olefins, cyclic hydrocarbons, and relatively high prportions of conjugated diolefinic hydrocarbons. The presence of conjugated dioleflnic hydrocarbons in the polymer formed under the influence of hydrogen fluoride as the sole catalyst is evidenced by the so-called specific extinction coefficient obtained by ultraviolet absorption analysis of the hydrocarbon products. In order to interpret the results of these ultra-violet absorption analyses, use is made of the specific extinction coemcient, which is equal to where Io=intensity of incident light (cell filled with isooctane) I=intensity of transmitted light (cell filled with solution of polymer in iso-octane solvent) C=concentration of polymer in cell in grams per liter L=length of cell path in centimeters fraction containing mono-olefins, may be agi- I tated with a mixture of hydrogen fluoride and a 4 compound soluble therein and selected from the group consisting of the acids of phosphorus and their anhydrides and esters in an autoclave or other reactor of suitable design.

Continuous operation of my process may be carried out by passing a mixture of an olefincontaining hydrocarbon fraction and a mixture of hydrogen fluoride and a spacing agent through a suitable reactor or group of reactors, separating liquid polymers from unconverted olefins and catalyst mixture and recycling the unconverted olefins and catalyst mixture to the polymerization zone of the process. It is usually necessary to include a cooling zone or other heat exchange means in the polymerization zone or between such zones if a multiple polymerization reactor system is employed.

From the statements hereinabove set forth concerning the types of substantially non-oxidizing compounds which may be employed as diluents or spacing materials for hydrogen fluoride, it will be evident that a large number of catalyst composites of various compositions may be made according to the needs of different polymerization reactions but the difierent diluents or spacing agents are not necessarily equivalent in their action.

. While in many cases the activity of the composite polymerizing catalyst employed is due principally to the hydrogen fluoride contained therein, it is recognized that the substantially non-oxidizing compounds added thereto may at times exert a definite chemical influence upon the reactions other than merely moderating the effect of the hydrogen fluoride. It is also evident that the selection of any particular diluent or mixture of diluents for use with hydrogen fluoride is determined largely by solubility relations, the ease of polymerizing the oleflnic hydrocarbons involved, the general operating conditions, and the matter of economy in the cost of the reagents.

The following example is given to indicate results obtained by the present process, although with no intention of limiting the scope of the invention in exact correspondence with the numerical results.

150 grams of propylene, '74 grams of liquid hydrogen fluoride of 99% concentration, and 20 grams of pyrophosphoric acid were contacted at C. for 2 hours in a autoclave equipped with a pressure-sealed stirring device. The reaction product resulting from this treatment was separated into a hydrocarbon layer and a used catalyst layer. The liquid hydrocarbon product which had about the same weight as that of the propylene charged was washed with caustic soda solution and with water and was then distilled to remove a gasoline fraction of 204 C. end point. The washed and dried polymer had a refractive index, n of 1.4440, a fluorine content of 0.37% by weight, a bromine number of 37, and an average molecular Weight of 236.

The reaction product from this run was also subjected to an ultra-violet absorption analysis in which the specific extinction coeflicients were determined for wave lengths between 220 and 275 m These results show that the polymer formed in the presence of my composite catalyst is less conplex and contains a lower percentage of conjugated double bonds than present in similar polymer produced at the same reaction temperature in the presence of anhydrous hydrogen fluoride. The operating conditions used in these runs with 'thehydrogen fluoride-pyrophosphoric acid catalyst and with'hydrogen fluoride alone and also a summary of the results obtained in these runs are given in the following table.

Table Run No 1 2 Temperature, C 95 95 Contact Time, Hours 2 2 Charged grams:

Propylene 150 150 Hydrogen Fluoride 74 87 Pyrophosphoric Acid 21 Recovered Liquid (a) (b) Properties of Hydrocarbon Produc Wt. per cent Fluorine .37 .12

Bromine number 37 79 Molecular weight 235 240 Cale. Br. Number for found N. V\ 67 67 V Wt. per cent 204 C. E. P. Gasoline. 22 22 Ultra-violet absorption analysis Specifi Extinction Coefficient Wave Length, m

(a) The liquid product, after allowing for losses, was equal to the propylene charged except for a trace of the propylene, (less than 1% which was converted to isopropyl fluoride.

(b) Same as note (41) except that 3%, on a molar basis, of the propylene charged was converted to isopropyl fluoride.

The foregoing specification and example indicate the character of the process of the present invention and the nature of the results obtained, although neither section is introduced to unduly limit the generally broad scope of the invention.

I claim as my invention:

1. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein, in an amount of from about 1% to about 50% by weight of a substantially nonoxidizlng compound soluble in liquid hydrogen fluoride and selected from the group consisting of the acids of phosphorus and their anhydrides and esters.

2. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein an acid of phosphorus in an amount of from about 1% to about by weight of the hydrogen fluoride.

3. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein a phosphoric acid in an amount of from about 1% to about 50% by weight of the hydrogen fluoride.

4. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein pyrophosphoric acid in an amount of from about 1% to about 50% by weight of the hydrogen fluoride.

5. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein an anhydrlde of an acid of phosphorus in an amount of from about 1% to about 50% by weight of the hydrogen fluoride.

6. A composition of matter consisting essentially of liquid hydrogen fluoride having dissolved therein an ester of an acid of phosphorus in an amount of from about 1% to about 50% by weight of the hydrogen fluoride.

CARL B. LINN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,181,640 Deanesly et al Nov. 28, 1939 2,398,905 Linn I Apr. 23, 1946 2,421,951 Linn II June 10, 1947 OTHER REFERENCES Mellors Inorganic and Theoretical Chemistry, Longmans, 1927, vol. 8, page 944. (Copy in Div. 59.) 

